ALSA: Revert "ALSA: snd-usb-caiaq: Set default input mode of A4DJ"
[safe/jmp/linux-2.6] / net / ipv4 / ip_gre.c
index b902ef5..fe381d1 100644 (file)
@@ -14,6 +14,7 @@
 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
+#include <linux/slab.h>
 #include <asm/uaccess.h>
 #include <linux/skbuff.h>
 #include <linux/netdevice.h>
    solution, but it supposes maintaing new variable in ALL
    skb, even if no tunneling is used.
 
-   Current solution: t->recursion lock breaks dead loops. It looks
-   like dev->tbusy flag, but I preferred new variable, because
-   the semantics is different. One day, when hard_start_xmit
-   will be multithreaded we will have to use skb->encapsulation.
+   Current solution: HARD_TX_LOCK lock breaks dead loops.
 
 
 
@@ -128,7 +126,7 @@ static int ipgre_tunnel_bind_dev(struct net_device *dev);
 
 #define HASH_SIZE  16
 
-static int ipgre_net_id;
+static int ipgre_net_id __read_mostly;
 struct ipgre_net {
        struct ip_tunnel *tunnels[4][HASH_SIZE];
 
@@ -159,8 +157,13 @@ struct ipgre_net {
 #define tunnels_r      tunnels[2]
 #define tunnels_l      tunnels[1]
 #define tunnels_wc     tunnels[0]
+/*
+ * Locking : hash tables are protected by RCU and a spinlock
+ */
+static DEFINE_SPINLOCK(ipgre_lock);
 
-static DEFINE_RWLOCK(ipgre_lock);
+#define for_each_ip_tunnel_rcu(start) \
+       for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
 
 /* Given src, dst and key, find appropriate for input tunnel. */
 
@@ -178,7 +181,7 @@ static struct ip_tunnel * ipgre_tunnel_lookup(struct net_device *dev,
                       ARPHRD_ETHER : ARPHRD_IPGRE;
        int score, cand_score = 4;
 
-       for (t = ign->tunnels_r_l[h0^h1]; t; t = t->next) {
+       for_each_ip_tunnel_rcu(ign->tunnels_r_l[h0 ^ h1]) {
                if (local != t->parms.iph.saddr ||
                    remote != t->parms.iph.daddr ||
                    key != t->parms.i_key ||
@@ -203,7 +206,7 @@ static struct ip_tunnel * ipgre_tunnel_lookup(struct net_device *dev,
                }
        }
 
-       for (t = ign->tunnels_r[h0^h1]; t; t = t->next) {
+       for_each_ip_tunnel_rcu(ign->tunnels_r[h0 ^ h1]) {
                if (remote != t->parms.iph.daddr ||
                    key != t->parms.i_key ||
                    !(t->dev->flags & IFF_UP))
@@ -227,7 +230,7 @@ static struct ip_tunnel * ipgre_tunnel_lookup(struct net_device *dev,
                }
        }
 
-       for (t = ign->tunnels_l[h1]; t; t = t->next) {
+       for_each_ip_tunnel_rcu(ign->tunnels_l[h1]) {
                if ((local != t->parms.iph.saddr &&
                     (local != t->parms.iph.daddr ||
                      !ipv4_is_multicast(local))) ||
@@ -253,7 +256,7 @@ static struct ip_tunnel * ipgre_tunnel_lookup(struct net_device *dev,
                }
        }
 
-       for (t = ign->tunnels_wc[h1]; t; t = t->next) {
+       for_each_ip_tunnel_rcu(ign->tunnels_wc[h1]) {
                if (t->parms.i_key != key ||
                    !(t->dev->flags & IFF_UP))
                        continue;
@@ -279,8 +282,9 @@ static struct ip_tunnel * ipgre_tunnel_lookup(struct net_device *dev,
        if (cand != NULL)
                return cand;
 
-       if (ign->fb_tunnel_dev->flags & IFF_UP)
-               return netdev_priv(ign->fb_tunnel_dev);
+       dev = ign->fb_tunnel_dev;
+       if (dev->flags & IFF_UP)
+               return netdev_priv(dev);
 
        return NULL;
 }
@@ -314,10 +318,10 @@ static void ipgre_tunnel_link(struct ipgre_net *ign, struct ip_tunnel *t)
 {
        struct ip_tunnel **tp = ipgre_bucket(ign, t);
 
+       spin_lock_bh(&ipgre_lock);
        t->next = *tp;
-       write_lock_bh(&ipgre_lock);
-       *tp = t;
-       write_unlock_bh(&ipgre_lock);
+       rcu_assign_pointer(*tp, t);
+       spin_unlock_bh(&ipgre_lock);
 }
 
 static void ipgre_tunnel_unlink(struct ipgre_net *ign, struct ip_tunnel *t)
@@ -326,9 +330,9 @@ static void ipgre_tunnel_unlink(struct ipgre_net *ign, struct ip_tunnel *t)
 
        for (tp = ipgre_bucket(ign, t); *tp; tp = &(*tp)->next) {
                if (t == *tp) {
-                       write_lock_bh(&ipgre_lock);
+                       spin_lock_bh(&ipgre_lock);
                        *tp = t->next;
-                       write_unlock_bh(&ipgre_lock);
+                       spin_unlock_bh(&ipgre_lock);
                        break;
                }
        }
@@ -479,7 +483,7 @@ static void ipgre_err(struct sk_buff *skb, u32 info)
                break;
        }
 
-       read_lock(&ipgre_lock);
+       rcu_read_lock();
        t = ipgre_tunnel_lookup(skb->dev, iph->daddr, iph->saddr,
                                flags & GRE_KEY ?
                                *(((__be32 *)p) + (grehlen / 4) - 1) : 0,
@@ -497,7 +501,7 @@ static void ipgre_err(struct sk_buff *skb, u32 info)
                t->err_count = 1;
        t->err_time = jiffies;
 out:
-       read_unlock(&ipgre_lock);
+       rcu_read_unlock();
        return;
 }
 
@@ -576,7 +580,7 @@ static int ipgre_rcv(struct sk_buff *skb)
 
        gre_proto = *(__be16 *)(h + 2);
 
-       read_lock(&ipgre_lock);
+       rcu_read_lock();
        if ((tunnel = ipgre_tunnel_lookup(skb->dev,
                                          iph->saddr, iph->daddr, key,
                                          gre_proto))) {
@@ -650,22 +654,23 @@ static int ipgre_rcv(struct sk_buff *skb)
                ipgre_ecn_decapsulate(iph, skb);
 
                netif_rx(skb);
-               read_unlock(&ipgre_lock);
+               rcu_read_unlock();
                return(0);
        }
        icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
 
 drop:
-       read_unlock(&ipgre_lock);
+       rcu_read_unlock();
 drop_nolock:
        kfree_skb(skb);
        return(0);
 }
 
-static int ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
+static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
 {
        struct ip_tunnel *tunnel = netdev_priv(dev);
-       struct net_device_stats *stats = &tunnel->dev->stats;
+       struct net_device_stats *stats = &dev->stats;
+       struct netdev_queue *txq = netdev_get_tx_queue(dev, 0);
        struct iphdr  *old_iph = ip_hdr(skb);
        struct iphdr  *tiph;
        u8     tos;
@@ -678,11 +683,6 @@ static int ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
        __be32 dst;
        int    mtu;
 
-       if (tunnel->recursion++) {
-               stats->collisions++;
-               goto tx_error;
-       }
-
        if (dev->type == ARPHRD_ETHER)
                IPCB(skb)->flags = 0;
 
@@ -794,7 +794,7 @@ static int ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
                }
 
                if (mtu >= IPV6_MIN_MTU && mtu < skb->len - tunnel->hlen + gre_hlen) {
-                       icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev);
+                       icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
                        ip_rt_put(rt);
                        goto tx_error;
                }
@@ -811,16 +811,17 @@ static int ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
                        tunnel->err_count = 0;
        }
 
-       max_headroom = LL_RESERVED_SPACE(tdev) + gre_hlen;
+       max_headroom = LL_RESERVED_SPACE(tdev) + gre_hlen + rt->u.dst.header_len;
 
        if (skb_headroom(skb) < max_headroom || skb_shared(skb)||
            (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
                struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
+               if (max_headroom > dev->needed_headroom)
+                       dev->needed_headroom = max_headroom;
                if (!new_skb) {
                        ip_rt_put(rt);
-                       stats->tx_dropped++;
+                       txq->tx_dropped++;
                        dev_kfree_skb(skb);
-                       tunnel->recursion--;
                        return NETDEV_TX_OK;
                }
                if (skb->sk)
@@ -888,7 +889,6 @@ static int ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
        nf_reset(skb);
 
        IPTUNNEL_XMIT();
-       tunnel->recursion--;
        return NETDEV_TX_OK;
 
 tx_error_icmp:
@@ -897,7 +897,6 @@ tx_error_icmp:
 tx_error:
        stats->tx_errors++;
        dev_kfree_skb(skb);
-       tunnel->recursion--;
        return NETDEV_TX_OK;
 }
 
@@ -951,7 +950,7 @@ static int ipgre_tunnel_bind_dev(struct net_device *dev)
                        addend += 4;
        }
        dev->needed_headroom = addend + hlen;
-       mtu -= dev->hard_header_len - addend;
+       mtu -= dev->hard_header_len + addend;
 
        if (mtu < 68)
                mtu = 68;
@@ -1148,12 +1147,9 @@ static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
 
        if (saddr)
                memcpy(&iph->saddr, saddr, 4);
-
-       if (daddr) {
+       if (daddr)
                memcpy(&iph->daddr, daddr, 4);
-               return t->hlen;
-       }
-       if (iph->daddr && !ipv4_is_multicast(iph->daddr))
+       if (iph->daddr)
                return t->hlen;
 
        return -t->hlen;
@@ -1288,39 +1284,33 @@ static void ipgre_fb_tunnel_init(struct net_device *dev)
 }
 
 
-static struct net_protocol ipgre_protocol = {
+static const struct net_protocol ipgre_protocol = {
        .handler        =       ipgre_rcv,
        .err_handler    =       ipgre_err,
        .netns_ok       =       1,
 };
 
-static void ipgre_destroy_tunnels(struct ipgre_net *ign)
+static void ipgre_destroy_tunnels(struct ipgre_net *ign, struct list_head *head)
 {
        int prio;
 
        for (prio = 0; prio < 4; prio++) {
                int h;
                for (h = 0; h < HASH_SIZE; h++) {
-                       struct ip_tunnel *t;
-                       while ((t = ign->tunnels[prio][h]) != NULL)
-                               unregister_netdevice(t->dev);
+                       struct ip_tunnel *t = ign->tunnels[prio][h];
+
+                       while (t != NULL) {
+                               unregister_netdevice_queue(t->dev, head);
+                               t = t->next;
+                       }
                }
        }
 }
 
-static int ipgre_init_net(struct net *net)
+static int __net_init ipgre_init_net(struct net *net)
 {
+       struct ipgre_net *ign = net_generic(net, ipgre_net_id);
        int err;
-       struct ipgre_net *ign;
-
-       err = -ENOMEM;
-       ign = kzalloc(sizeof(struct ipgre_net), GFP_KERNEL);
-       if (ign == NULL)
-               goto err_alloc;
-
-       err = net_assign_generic(net, ipgre_net_id, ign);
-       if (err < 0)
-               goto err_assign;
 
        ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "gre0",
                                           ipgre_tunnel_setup);
@@ -1341,27 +1331,26 @@ static int ipgre_init_net(struct net *net)
 err_reg_dev:
        free_netdev(ign->fb_tunnel_dev);
 err_alloc_dev:
-       /* nothing */
-err_assign:
-       kfree(ign);
-err_alloc:
        return err;
 }
 
-static void ipgre_exit_net(struct net *net)
+static void __net_exit ipgre_exit_net(struct net *net)
 {
        struct ipgre_net *ign;
+       LIST_HEAD(list);
 
        ign = net_generic(net, ipgre_net_id);
        rtnl_lock();
-       ipgre_destroy_tunnels(ign);
+       ipgre_destroy_tunnels(ign, &list);
+       unregister_netdevice_many(&list);
        rtnl_unlock();
-       kfree(ign);
 }
 
 static struct pernet_operations ipgre_net_ops = {
        .init = ipgre_init_net,
        .exit = ipgre_exit_net,
+       .id   = &ipgre_net_id,
+       .size = sizeof(struct ipgre_net),
 };
 
 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
@@ -1475,14 +1464,14 @@ static void ipgre_tap_setup(struct net_device *dev)
 
        ether_setup(dev);
 
-       dev->netdev_ops         = &ipgre_netdev_ops;
+       dev->netdev_ops         = &ipgre_tap_netdev_ops;
        dev->destructor         = free_netdev;
 
        dev->iflink             = 0;
        dev->features           |= NETIF_F_NETNS_LOCAL;
 }
 
-static int ipgre_newlink(struct net_device *dev, struct nlattr *tb[],
+static int ipgre_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[],
                         struct nlattr *data[])
 {
        struct ip_tunnel *nt;
@@ -1536,25 +1525,29 @@ static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
                if (t->dev != dev)
                        return -EEXIST;
        } else {
-               unsigned nflags = 0;
-
                t = nt;
 
-               if (ipv4_is_multicast(p.iph.daddr))
-                       nflags = IFF_BROADCAST;
-               else if (p.iph.daddr)
-                       nflags = IFF_POINTOPOINT;
+               if (dev->type != ARPHRD_ETHER) {
+                       unsigned nflags = 0;
 
-               if ((dev->flags ^ nflags) &
-                   (IFF_POINTOPOINT | IFF_BROADCAST))
-                       return -EINVAL;
+                       if (ipv4_is_multicast(p.iph.daddr))
+                               nflags = IFF_BROADCAST;
+                       else if (p.iph.daddr)
+                               nflags = IFF_POINTOPOINT;
+
+                       if ((dev->flags ^ nflags) &
+                           (IFF_POINTOPOINT | IFF_BROADCAST))
+                               return -EINVAL;
+               }
 
                ipgre_tunnel_unlink(ign, t);
                t->parms.iph.saddr = p.iph.saddr;
                t->parms.iph.daddr = p.iph.daddr;
                t->parms.i_key = p.i_key;
-               memcpy(dev->dev_addr, &p.iph.saddr, 4);
-               memcpy(dev->broadcast, &p.iph.daddr, 4);
+               if (dev->type != ARPHRD_ETHER) {
+                       memcpy(dev->dev_addr, &p.iph.saddr, 4);
+                       memcpy(dev->broadcast, &p.iph.daddr, 4);
+               }
                ipgre_tunnel_link(ign, t);
                netdev_state_change(dev);
        }
@@ -1672,15 +1665,16 @@ static int __init ipgre_init(void)
 
        printk(KERN_INFO "GRE over IPv4 tunneling driver\n");
 
-       if (inet_add_protocol(&ipgre_protocol, IPPROTO_GRE) < 0) {
+       err = register_pernet_device(&ipgre_net_ops);
+       if (err < 0)
+               return err;
+
+       err = inet_add_protocol(&ipgre_protocol, IPPROTO_GRE);
+       if (err < 0) {
                printk(KERN_INFO "ipgre init: can't add protocol\n");
-               return -EAGAIN;
+               goto add_proto_failed;
        }
 
-       err = register_pernet_gen_device(&ipgre_net_id, &ipgre_net_ops);
-       if (err < 0)
-               goto gen_device_failed;
-
        err = rtnl_link_register(&ipgre_link_ops);
        if (err < 0)
                goto rtnl_link_failed;
@@ -1695,9 +1689,9 @@ out:
 tap_ops_failed:
        rtnl_link_unregister(&ipgre_link_ops);
 rtnl_link_failed:
-       unregister_pernet_gen_device(ipgre_net_id, &ipgre_net_ops);
-gen_device_failed:
        inet_del_protocol(&ipgre_protocol, IPPROTO_GRE);
+add_proto_failed:
+       unregister_pernet_device(&ipgre_net_ops);
        goto out;
 }
 
@@ -1705,9 +1699,9 @@ static void __exit ipgre_fini(void)
 {
        rtnl_link_unregister(&ipgre_tap_ops);
        rtnl_link_unregister(&ipgre_link_ops);
-       unregister_pernet_gen_device(ipgre_net_id, &ipgre_net_ops);
        if (inet_del_protocol(&ipgre_protocol, IPPROTO_GRE) < 0)
                printk(KERN_INFO "ipgre close: can't remove protocol\n");
+       unregister_pernet_device(&ipgre_net_ops);
 }
 
 module_init(ipgre_init);